MORPHOMETRIC STUDY OF HYPOGLOSSAL CANAL OF OCCIPITAL BONE IN DRY SKULLS OF SOUTH INDIA Vinay KV * 1 ,  Swathi 2 , Denia MY 3 , Sachin KS 2 . *1 Associate Professor, Department of Anatomy, K. S. Hegde Medical Academy, Nitte University, Mangaluru, Karnataka. India. 2 Assistant Professor, Department of Anatomy, K. S. Hegde Medical Academy, Nitte University, Mangaluru, Karnataka. India. 3 Second  MBBS student, Department of Anatomy, K. S. Hegde Medical Academy, Nitte University, Mangaluru, Karnataka. India. Correspondence   Address:   Dr.   Vinay   Kumar.   V,   Associate   Professor,   Department   of   Anatomy,   K.   S.   Hegde   Medical   Academy,   Nitte   University,   Deralakatte, Mangaluru, Karnataka, India. Pin- 575018. Ph: +917795767676, E-Mail:  dr7795767676@gmail.com. ABSTRACT : The   hypoglossal   nerve   is   the   twelth   cranial   nerve   cranial   nerve   XII   which   is   a   motor   nerve   supplying   the   muscles   of   tongue.   At   the   skull   base,   it   passes through   the   hypoglossal   canal   (HC).   The   HC   has   different   shapes   &   dimensions.   The   knowledge   about   these   dimensions   of   HC   is   very   important   for neurosurgeons   &   radiologists.   The   present   study   was   done   on   50   dry   adult   skulls.   The   length,   diameter,   distance   of   hypoglossal   canal   from   occipital condyles   were   measured   using   a   digital   Vernier’s   calipers.   The   parameters   were   measured   separately   on   right   &   left   side,   tabulated   &   analysed   statistically.     The   mean   length   of   HC   was   12.55mm.   The   mean   diameter   HC   at   its   intracranial   &   extracranial   end   was   7.5   &   7.6mm   respectively.   The   mean   distance   from intracranial   end   of   HC   to   anterior   &   posterior   end   of   occipital   condyle   was   12.7   &   12.9   mm   respectively.   The   mean   distance   from   intracranial   end   of   HC   to inferior   end   of   occipital   condyle   was   11.98   &   12.32mm   on   right   &   left   side   respectively   which   was   statistically   significant.   The   study   of   morphometry   of   HC & its location is important to anatomists, anthropologists, forensic experts & clinicians KEY WORDS: hypoglossal canal, occipital condyle, morphometry, Skull base, Foramina. References 1 . Bulsara   KR,   Asaoka   K,   Aliabadi   H,   Kanaly   C,   Friedman   A,   Fukushima   T.   Morphometric   three   dimensional   computed   tomography   anatomy   of   the hypoglossal canal. Neurosurg Rev. 2008;31:299-302. 2 . Gapert   R,   Black   S,   Last   J.   Sex   determination   from   the   foramen   magnum:   Discriminant   function   analysis   in   an   eighteenth   &   nineteenth   century   British sample. Int J Legal Med. 2009;123:25-33. 3 . Wen   HT,   Rhoton   AL,   Katsuta   T,   et   al.,   Microsurgical   anatomy   of   the   transcondylar   extensions   of   the   far-lateral   approach.   J   Neurosurg.   1997;87:555- 585. 4 . Gilsbach JM, Sure U, Mann W. The supracondylar approach to the jugular tubercle and hypoglossal canal.  Surg Neurol. 1998;50:563-570. 5 . Wanebo JE, Chicoine MR. Quantitative analysis of the transcondylar approach to the foramen magnum.  Neurosurgery. 2001; 49:934-943. 6 . Katsuta   T,   Matsushima   T,   Wen   HT   et   al.,   Trajectory   of   the   hypoglossal   canal:   significance   for   the   transcondylar   approach.   Neurol   Med   Chir   (Tokyo). 2000;40:206-210. 7 . Karasu A, Cansever T, Batay F, Sabanci PA, AlMefty O. The microsurgical anatomy of the hypoglossal canal. Surg Radiol Anat. 2009;31:363-7. 8 . Wanebo JE, Chicoine MR. Quantitative analysis of the transcondylar approach to the foramen magnum. Neurosurgery. 2001;49:934-943. 9 . Katsuta   T,   Matsushima   T,   Wen   HT   et   al.,   Trajectory   of   the   hypoglossal   canal:   significance   for   the   transcondylar   approach.   Neurol   Med   Chir   (Tokyo). 2000;40:206-210. 1 0 . Hadley   KS,   Shelton   C.   Infratemporal   fossa   approach   to   the   hypoglossal   canal:   practical   landmarks   for   elusive   anatomy.   Laryngoscope.   2004;114:1648- 1651. 1 1 . Berlis A, Putz R, Schumacher M. Direct & CT measurements of canals and foramina of the skull base. Br J Radiol. 1992;65:653-661. 1 2 . Kizilkanat   ED,   Boyan   N,   Soames   R,   Oguz   O.   Morphometry   of   the   Hypoglossal   Canal,   Occipital   Condyle   &   Foramen   Magnum.   Neurosurg   Q.   2006;16(3): 121-125. 1 3 . Muthukumar   N,   Swaminathan   R,   Venkatesh   G   et   al.,   A   morphometric   analysis   of   the   foramen   magnum   region   as   it   relates   to   the   transcondylar approach. Acta Neurochir (Wien). 2005;147: 889-895. 1 4 . Berge JK, Bergman RA. Variations in size and in symmetry of foramina of the human skull. Clin Anat. 2001;14: 406-413.